Diabetes and related complications have enormous personal and health care system consequences. Efficient and effective interventions are needed to enhance type 2 diabetes patients' self-management of their disease. This study will use a randomized two-group, pretest-posttest design to determine if an emailed self-determination theory-based intervention is effective in increasing exercise behavior in type 2 diabetes patients. Participants will all be assessed on pretest measures then randomly assigned to either usual care or an emailed exercise intervention. The treatment group will receive weekly stage-matched autonomy-supportive educational emails on exercise from the principal investigator (PI), who is a Certified Diabetes Educator (CDE). The duration of the intervention will be 12 weeks. Outcomes for both groups will be measured at baseline, the end of the12 week intervention period, and again 24 weeks after entry in the study. The independent variable is the emailed exercise intervention. The dependent variables are self-reported exercise behavior, DigiWalker data, blood glucose control as measured by hemoglobin A1 c, perceived autonomy as measured by the Treatment Self-Regulation Questionnaire, perceived competence as determined by the Perceived Competence for Diabetes Scale, and stages of exercise behavior as measured on the Stages of Exercise Scale. Study results have the potential to inform future research and nursing practice with adults with diabetes.